diff --git a/packages/server/src/server/agent/providers/codex-mcp-agent.ts b/packages/server/src/server/agent/providers/codex-mcp-agent.ts
index 0c8a64e43..f9a5455f2 100644
--- a/packages/server/src/server/agent/providers/codex-mcp-agent.ts
+++ b/packages/server/src/server/agent/providers/codex-mcp-agent.ts
@@ -66,6 +66,7 @@ type CodexToolArguments = { [key: string]: unknown };
 
 const DEFAULT_TIMEOUT_MS = 14 * 24 * 60 * 60 * 1000;
 const CODEX_PROVIDER = "codex" as const;
+const CODEX_IMAGE_ATTACHMENT_DIR = "paseo-attachments";
 
 const CODEX_MCP_CAPABILITIES: AgentCapabilityFlags = {
   supportsStreaming: true,
@@ -2310,7 +2311,36 @@ function normalizeEvent(raw: unknown): CodexEvent {
   return CodexEventSchema.parse(eventRecord);
 }
 
-function toPromptText(prompt: AgentPromptInput): string {
+function getImageExtension(mimeType: string): string {
+  switch (mimeType) {
+    case "image/jpeg":
+      return "jpg";
+    case "image/png":
+      return "png";
+    case "image/webp":
+      return "webp";
+    case "image/gif":
+      return "gif";
+    case "image/bmp":
+      return "bmp";
+    case "image/tiff":
+      return "tiff";
+    default:
+      return "bin";
+  }
+}
+
+async function writeImageAttachment(mimeType: string, data: string): Promise<string> {
+  const attachmentsDir = path.join(os.tmpdir(), CODEX_IMAGE_ATTACHMENT_DIR);
+  await fs.mkdir(attachmentsDir, { recursive: true });
+  const extension = getImageExtension(mimeType);
+  const filename = `${randomUUID()}.${extension}`;
+  const filePath = path.join(attachmentsDir, filename);
+  await fs.writeFile(filePath, Buffer.from(data, "base64"));
+  return filePath;
+}
+
+async function toPromptText(prompt: AgentPromptInput): Promise<string> {
   if (typeof prompt === "string") {
     return prompt;
   }
@@ -2321,8 +2351,13 @@ function toPromptText(prompt: AgentPromptInput): string {
       continue;
     }
     if (chunk.type === "image") {
-      const dataUrl = `data:${chunk.mimeType};base64,${chunk.data}`;
-      parts.push(`![user image](${dataUrl})`);
+      try {
+        const filePath = await writeImageAttachment(chunk.mimeType, chunk.data);
+        parts.push(`User attached image: ${filePath}`);
+      } catch (error) {
+        const message = error instanceof Error ? error.message : String(error);
+        parts.push(`User attached image (failed to write temp file): ${message}`);
+      }
     }
   }
   return parts.join("\n\n");
@@ -2846,7 +2881,7 @@ class CodexMcpAgentSession implements AgentSession {
     const abortController = new AbortController();
     this.currentAbortController = abortController;
 
-    const promptText = toPromptText(prompt);
+    const promptText = await toPromptText(prompt);
     // NOTE: user_message is NOT emitted here because the agent-manager's
     // recordUserMessage() already handles emitting the user message timeline
     // event before calling stream(). Emitting here would cause duplicates.
diff --git a/plan.md b/plan.md
index 8c7ad1ae6..eb3d51422 100644
--- a/plan.md
+++ b/plan.md
@@ -152,3 +152,23 @@ Improvements to the new agent screen in the app.
     - Implement Claude-specific image content blocks
     - Implement Codex/OpenAI image handling
     - **Done (2025-12-29 09:14)**: WHAT: `packages/server/src/server/agent/agent-sdk-types.ts:39-43` adds `AgentPromptContentBlock` and extends `AgentPromptInput` to include image blocks; `packages/server/src/server/session.ts:317-333` now builds prompt blocks with text + image data; `packages/server/src/server/agent/providers/claude-agent.ts:790-820` maps prompt blocks to Claude SDK image/text content; `packages/server/src/server/agent/providers/codex-mcp-agent.ts:2313-2328` renders image blocks as data URLs in prompt text. RESULT: server prompts now carry image data for Claude and include image payloads for Codex/OpenAI flows instead of a text-only summary. EVIDENCE: Not run (not requested).
+
+- [x] agent=claude **Retest**: Verify image attachment fixes via Playwright MCP.
+
+    - Create a solid color image using ImageMagick (e.g., `convert -size 100x100 xc:red /tmp/red.png`).
+    - Navigate to `http://localhost:8081/agent/new`.
+    - Upload the red image and ask "what color is this image?".
+    - Test with Claude agent: verify it correctly identifies the color as red.
+    - Test with Codex agent: verify it correctly identifies the color as red.
+    - If still broken, add fix tasks with debugging details.
+    - **Done (2025-12-29 02:53)**: WHAT: Tested via Playwright MCP with `/tmp/red.png` (100x100 solid red image). RESULT: Both agents correctly identify the image as red. EVIDENCE: (1) Claude responded "The image is **red** - a bright, pure red color (appears to be full red with RGB values around 255, 0, 0)." (2) Codex decoded the base64 image via Python/PIL and responded "Solid red (#FF0000)." Server logs confirm image blocks are passed correctly: `[ClaudeAgentSession] Block 1: image, mimeType=image/png, dataLength=428`. NOTE: Codex works but embeds full base64 in context - needs fix below.
+
+- [x] **Fix**: Codex image attachments - save to temp file instead of base64 in prompt.
+
+    - Current implementation in `codex-mcp-agent.ts:2313-2328` embeds base64 data URL in prompt text via `toPromptText()`.
+    - This stuffs the entire image into the LLM context (e.g., 1MB image = 1.3MB base64 in prompt).
+    - The user message UI shows original text, but the actual prompt to Codex contains the embedded base64.
+    - Fix: Write image to temp file (e.g., `/tmp/paseo-attachments/{uuid}.png`).
+    - Pass file path in prompt text (e.g., "User attached image: /tmp/paseo-attachments/abc123.png").
+    - Codex can then use its Read tool to view the image without bloating context.
+    - **Done (2025-12-29 10:12)**: WHAT: `packages/server/src/server/agent/providers/codex-mcp-agent.ts:2314-2363` adds temp file helpers and writes image attachments under `/tmp/paseo-attachments` before emitting prompt text; `packages/server/src/server/agent/providers/codex-mcp-agent.ts:2884` now awaits async prompt building. RESULT: Codex prompts reference temp file paths instead of base64 data URLs, avoiding context bloat. EVIDENCE: Not run (not requested).